Concrete finishing machine



July 31, 1962 .1.J. MORO-LIN ETAL 3,046,855

CONCRETE FINISHING MACHINE 2 Sheets-Sheet 1 Filed Dec. 19, 1957 July 31,1962 J. J. MoRo-L1N ETAL 3,046,855

CONCRETE FINISHING MACHINE Filed Dec. 19, 1957 2 Sheets-Sheet 2INVENTORSl 141 JbJe/a/ Mara -Lf effraie/M iam);

y @im United States Patent O 3,046,855 CONCRETE lilNiSfHNG MAC Joseph J.Moro-Lin, Glen Rock, and Leverette Hoeningtransen, East Paterson, NJ.,assignors to Kalman Floor Company, incorporated, New York, NX., acorporation of Delaware Filed Dec. 19, 1957, Ser. No. 763,94@ 8 Claims.(Cl. 94-45) This invention relates to apparatus for the surfacing ofplastic bodies and particularly to apparatus intended to be used forfinishing surfaces of concrete slabs such as oor slabs. This inventionis a modification on the apparatus disclosed and described in detail inour application Serial No. 682,716 led September 9, 1957.

Priorly, various types of mechanically operated mechanisms have beendeveloped which were designed and intended to reduce to the minimum thelamount of manual labor which must be expended and the time required toreduce to a true plane and impart the desired surface finish to plasticbodies such as concrete oors, walks and roadways. A number of thesemechanisms lhave come into widespread use, some particularly designedfor use on roadways and others primarily intended for employment in thesurfacing of floors. A known type of mechanically operated surfacemecha- Vm'sm comprises a work engaging member, a motor coupled to thework engaging member for rotating the work engaging member `and a handlewhich prevents rotation of the motor casing and constitutes a means formoving the implement over the surface of a concrete body in the desiredmanner.

One particular form of mechanism known in the fart includes a mechanismfor imparting 'to the rotating workengaging member high frequencyvibrations so that the plastic body below the apparatus is not onlysubjected to the action of the rotating disc but is subjected to highfrequency vibrations. Such -apparatus is highly effective and enablesthe user to properly surface a plastic body, such as a concrete floor,in a vastly improved manner. Thus, by the aid of the rotating andvibrating disc, an extremely dry concrete mixture may be surfaced, amixture having a low water-cement ratio that it cannot be surfaced byordinary means or methods since it is impossible to laterally displaceor horizontally push material from the higher areas of the concrete ontothe lower areas. The leveling of the floor surface is brought about byvertically depressing the higher areas instead of laterally displacingthese areas and the concrete slab or the like which is produced is ofsuperior construction, being more dense and free of voids. The surfaceis superior inasmuch as this method of leveling the Same results inbringing to the surface a relatively stiff paste of cement and fine sandbarely sufficient in thickness for the fine trowelling by hand. Theimproved method not only gives a `superior product but insuressubstantial surfacing in time and labor costs. However, we havediscovered that in employing vibratory and rotary motion to finish theconcrete, it is not always necessary to employ both vibratory and rotarymotion. For example, after the higher areas are vertically depressed andthe plastic body approaches a level surface then the vibratory motionmay be discontinued while maintaining the rotary motion to thus achievean extremely smooth surface. One example of rotary and vibratory surfaceiinishing machine is disclosed and described in detail in R. E. DavisPatent No. 2,386,843, issued October 16, 1945.

Briefly, in accordance with the invention disclosed in our abovementionedV application, `a concerte nishing machine is enclosed in astationary housing and provided with a cam plate associated with a wearor oor finishing plate. A group of spring biased plungers are mounted onthe housing and are operatively linked to the cam surfaces by means ofrollers mounted on the plungers. The prime mover or source of power forthe machine is coupled to the wear plate by means `of a splined shaftand a splined plate to impart rotary motion while permitting axialvibratory motion of the wear plate. The shaft is spring biased by ahelical shock absorber spring secured between the cam or master plateand the end of the shaft. The plungers are moved upwardly by themovement vof the rollers upon the cam surfaces and the motion of theplungers may be selectively discontinued by means of hydraulic cylindersand pistons located in the cylinders and each coupled to a plunger. Asthe cam plate is rotated by means of the Splined shaft, the rollers ridethe cam surfaces and the connected plungers move out of engagement withthe cam plate and return to the cam plate under the influence of theimpact springs. Thus, the energy imparted to the impact springs by thecam plate is imparted to the plungers to return the pluri-gers to thecam plate, thereby giving a vibratory lmotion to the connected wearplate.

In accordance with other aspects of the invention disclosed in our abovementioned application, the plungers may vbe moved away from the cam orundulation plate by the operator during the finishing operation suchthat the rollers are disengaged from the cam surfaces. The reciprocatingmotion of the plungers formerly caused by the cam plate is thusterminated. The operator may thus terminate the vibratory motionimparted to the Wear plate and hence to the concrete floor withoutmodifying the rotary operation.

In accordance with other yaspects of the invention dis- V closed in ourabove mentioned application, the plungers are spaced approximately aparton the housing of the machine while opposite pairs of the plungers areolfset a few degrees so that a beat frequency is generated by thecooperation of the plungers and the cam plate. By means of this beatfrequency, the number of vibrations imparted to the wear plate and henceto the floor is greatly increased without the requirement that the wearplate be rotated at exceedingly high speeds.

During subsequent tests we have determined that still further improvedresults may be achieved by increasing the vibrating frequency and impactyof the reciprocating plungers while actually decreasing the powerrequired to be imparted to the plungers. We have also discovered a novelpump mechanism for selectively controlling the actuation ofthereciprocating plungers. n

Accordingly, it is van object of this invention to provide an improvedconcrete finishing machine.

It is another object of this invention to provide an improved conoretefinishing machine which is adapted selectively .to apply vibratorymotion -to the concrete mass.

It is another object of lthis invention to provide an improvedvibratory-rotary concrete finishing machine which is simple in`construction and operation.

It is another `object of this invention to provide an improved concretefinishing machine in which vibratory motion of a higher frequency isimparted to the concrete mass from a single primemover yand thevibratory impact is increased without increasing the speed of the primemover and while decreasing the power required to be impanted to thereciprocating plungers.

It is another object `of this invention to provide` an improvedvibratory and rotary `concrete nishing machine which is simple inconstruction yand operation and thus economical yto build.

It is another object of this invention -to provide `an improved fiuidsystem for selectively controlling the actuation of the reciprocatingplungers.

It is another object of this invention to provide an imline 3 3, ofFIGURE 1.

aca-.6,855

proved uid pump for the fluid system which controls the actuation of thereciprocating plungers.

It is another object of this invention to provide the uid systempumpwitha piston which, in addition to pumping duid, also may ibe employed' tooperate selectively a valve lassoci-atedr'with the pump.

. It visja further object of this-invention to provide the fluid controlsystem of 4the machine with a piston which provides an `additional fluidpassageway for Lthe fluid when the piston moves to open the valveassociatedl with the pump. Y

[t isv a further object of this invention to provide the fluidcontrolsystem of the machine with a pump having Vcylinder and reducedthe eiective impact of our prior Ymachine,V do not lmove with thereciprocating plunger butare nevertheless actuable to raise the plungersso that the rollers will lbe disengaged from the cam surfaces on theWear plate.Y Such movement is possibile since the piston has ahollowtubular extension having an annular diange on the inner periphery whichengages an annular protrusion or shoulder onthe reciprocating plunger. Aplurality of curved members, such as metallic buttons, areV mounted inthe Wear plate between the cam surfaces and are engaged :bythe tip ofthe reciprocating plunger. Advantageously, these .buttons are locatedconcentrically with respect to the-cam surfaces andare positioned toengage the -tip of.I the plunger immediately after the associated roller'has passed over thecrest of the foam surfaces. The' buttons thus causethe reciprocating plunger to have va vibratory motion at a frequencyygreater than that produced-by the rollers `and cam surfaces alone.Further, since'the plunger is reciprocally mounted with respect to thefluid piston, the piston does not act was a damping device to reduce the'impact of the plungers;

It is another feature of this invention to provide undulatory surfaceson the Wear plate intermediate the cam surfaces to engage thereciprocating plungers and thus impart a greater frequency of vibrationthan could be achieved by the cam surfaces alone. Y

llt i-snanother feature of this invention -to provide undulatorysurfaces on the Wear plate concentrically arranged with respect to thecam surfaces, which undulatory surfaces engage the tip of thereciprocating plungers and thus increase the frequency of thereciprocation of the plungers Without increasing the speed of motion offthe Wear plate. j i

A complete understanding of this invention and of Vthese and variousother features thereof may =be gained of FIGURE 1 to a larger scale.

FIGURE Y3 is a `plan view, partly in section, taken on FIGURE 4 is aview taken along the lines 4-4 of FIGURESZandS.

FIGURE 5 is a view in elevation, vpartly in section, of the fluid pumpland a portion of the handle.

Referring now to the drawing, there is depicted one illustrativeembodiment of this invention. As shownrn FIGURE l, a concrete finishingmachine housing has a suitable prime mover 12 mounted thereon. Thisprime mover may be of `any convenient type such as an internal 4combustion engine Ior an electric motor. connected to prime mover l2 andhas a pulley le secured thereto to provide a means for operativelyconnecting the prime mover with the concrete contacting plate` as willbe subsequently explained. A shaft 20 is rotatably mounted in housing 22and has a pulley iii secured theret0. Pulleys 16 and 18 are oonnectedbymeans of a suitable V belt (not shown). on and secured to shaft 2uWithin housing 22. A wheel gear 23 is secured to vertical'shaft 24-andpositioned adjacent worm gear 2l so that Worm gear 21 drives wheel gear23 when shaft 20 is rotatated by the prime mover 12. Shaft 24 isrotatably mounted in housing 1Q: Drive plate 26 is secured to the lowerend of shaft 24 by means of nut 66.

Spaced around the periphery of drive plate 26 are aV Y plurality ofbolts 2S used to interconnect drive plate 26 and master plate 32.Resilient bushings surround each of bolts 28 and are held in place byplates 29 which are secured to plate 26 by bolts 3l. Bushings Si)provideVV means for coupling the plate 26 -to masterplate 32 whilejpreventing the vibration of master plate 32, from beingA transmitted tothe gears 21-and 23,.p1ime mover 1Z-and to the operator of the machine.Vibration of gears and the prime mover would cause excessive Wear.Addi'-,

tionally, this vibration, if allowed toY reach the handle,

would make the machine diiiic'ult forthe operator vto, K

. control.

:Wear plate 34, which contacts ythe rsurface to lbe` tin-V ished,isz-connectedto master plate 32 by means of suit-V Y able bolts 36. Aplurality of plunger assemblies 33 are mounted around the periphery ofhousing il?. Any convenient number of plunger assemblies may beemployed,

depending on the lfrequency of vibration desired. For

example, six may be employed and they maybe spacedl Y approximately 60apart. If itis vdesired to developa As best seeen in FIGURE 2, rollers42 are rotatably" mounted on the lower portion of plungers 40 and theserollers operatively engage cam surfaces 43 and 45. A plurality ofundulatory impact buttons 44 are concentrically arranged with respect tocam surfaces 43 and V45 in plate member 32. These impact buttons engagethe tips 47 of plungers 40 .to produce supplemental vibrations` as willbe subsequently explained.

Pistons 4S are slidably mounted in the upper housing of each vofjplungerassemblie'ss.Y These pistons include a tubular extension 52 havinganaxial passageway therethrough to permit the plungersV 40 reciprocatedrelative to the pistons and :to act as arguide member 'fortheyreciprocating plungersyt. A suit-able fluid seal '.Stl'is secured tothe lowerfportion off the outer-peripheryof piston 4S.'Iubular-extension-SZ also acts as a guide member for the reciprocatingplungers 40.' These Itubular extensions 52 have an annular shoulder 53on Vtheirinn'er Y surface. Shoulder 52 engages Iannular ring 55 -on theplungers 40 when the pistons 4# are moved )upwardly by the introductionof fluid between pistons `iS/and the housings of plunger lassemblies 38.This duid is pumped through uidrpassage 56 from a vpump convenientlylocated on the machine handle, which will be subsequently described. Theupward movement of pistons 48 disengages' the reciprocating plungersfrom the impact buttons 44 and disengages the rollers 42' irom the camsurfaces 43 and 45. Shoulders 53'areflocated lat .'a'point suicientlyremoved from they yupper, surfaces lof pistons A staan is A worm gear 21is mounted f 48 to permit the plungers to reciprocate freely when thepiston is in its lower position, as shown in FIG. 2. Fluid sealingwashers 57 and 58 are positioned in the housings of the plunger-assemblies 38 'to provide a fluid seal'between the housings and thetubular extensions 52.

Helical springs 62 surround a portion of each plunger 4t) 'and engageannular shoulders 63 of each plunger 4G' and the lower surface ofcylindrical member 64 which denes the upper portion of housing 1i) inthe regions of the plungers 40. The plunger assemblies 3S :are securedto housing 1@ by means of suitable bolts 65. The tops of plunger-assemblies 38 are defined by members 67 which are secured by suitablebolts 68.

In order to prevent the entry of foreign particles into the machinehousing, -a shield 70 is secured to the master plate 32 by means ofsuitable bolts '72. This shield is cylindrical in shape yand extendsfrom the master plate 32 to a region adjacent the lower surface ofhousing 10, thus preventing the entry of foreign matter between housing1i) land wear plate 32.

The operation of the reciprocating plungers. might be explained withregard to FlG. 4 which shows the relationship of cam surfaces 43 and 45and impact buttons 44. As shown in FGURE 4, rollersj42 co-operate withcam surface 45 to produce reciprocating motion of the piston 4G. Camsurface 45 includes a substantially flat trough 160 and a peak or crest102 at the termination of an incline plane 194, which plane is connectedto a trough 1G13. The entire length of a given cam surface is measuredfrom lone crest or peak to the next crest or peak and this length istermed the cam pitch. The extreme lower portion 166 of plunger 4i? isdisengaged from the undulatory buttons 44 when the rollers 42 ride up onthe incline planes 164 'as master plate 32 is rotated by the 102, theenergy stored in spring 62 is imparted to the plunger or piston 49,causing plunger -tip 106 to strike the undulatory Kbutton 44 as shown-in the middle dotted line of FlGURE 4 and thus impart vibratory motionto the master plate 32 each time the rollers 42 pass a pair of crests162.

Since the plungers 40' are not rigidly connected to pistons 48, -thesepistons do not move with the plungers. Thus, the plungers do not incurfrictional losses which might be introduced by the pistons sliding upand down the cylindrical chambers, as they would if the pistons weresecured to the plungers. Thus by virtue of the reduced drag, less poweris required to ydrive the reciprocating plungers than would be requiredif the pistons were secured to the plungers. Further, even though lesspower is required an increase impact force is obtained since the pistonsdo not slow the downward motion of the plungers. Advantageously, ahigher rate or frequency of impact is achieved by the use of the impactbuttons 44 which engage the tips 47 of plungers 4G' `and this increasedfrequency of impactV is achieved with less driving power than thedevices of the type disclosed in our application Serial No. 682,716tiled September 9, 1957.

Referring now to FIG. 5 there is depicted a portion of handle 80 havinga fluid pump 82 mounted thereon. 'I'his iiuid pump S2 is `connectedthrough a suitable flexible conduit or hose 84 to pipe S6 located withinhousing 1li. Pump `rassembly 82 includes a iiuid reservoir 85, a pistonhousing 87, Ia pair of piston members 89 and 91, a ball check valve 93,biased into apclosed position by spring 95, and a pump handle assembly97. Fluid reservoir 85 is provided with va ball type vacuum relief valve99 and a cover 101 which threadably engages the reservoir 85 to permituid to fbe inserted in the reservoir. Piston member 89 is provided with-a fluid seal 103 located in an annular recess 195 to prevent thepassage of fluid beto its seat.

ture 113 in reservoir 85 when piston member 89 is at.

the forward end of its stroke.

Advantageously, piston member 91 `has a reduced portion 115 whichprovides a passageway between member 91 and the inner wall of pistonmember 89. This passageway is connected with passageway -111 and alsoconnects with hose or conduit 84 when member 89 is advanced by rotationof knob 199 to unseat ball check valve 93. The normal position of member91 is that shown in FIG. 5 in which enlarged member .117 acts as a valveto seal the passageway between piston members S9 and 91 so that the twopiston members may act as a single unit to pump fluid from reservoir 82into hose 84.

The operation of the uid pump is `as follows: When the handle assembly97 is manually moved to the opposite end of its stroke, as shown in thedotted outline, piston members 89 and 91 are withdrawn beyond aperture113 and iluid passes from reservoir S5 into the chamber thus providedbetween the ends of piston members S9 and 91 and ball check valve 93.When the handle assembly 97 is returned to the end of its stroke, asshown in solid lines, the iiuid in the chamber is subjected to pressureand fthe fluid causes the valve 93 to be unseated. When valve 93 isunseated, the uid passes around the Valve into conduit 34. When thepiston reaches the end of its stroke, the ball check valve is againforced into its seated position. by spring 95 and the cycle may berepeated `until sufhcient iluid pressure is built up within chambers 41to cause the pistons 48 to move into their uppermost position. Pistons48 thus lift plunger tips 47 out of engagement with impact buttons 44and rollers 42 out of engagement with cam surfaces '43 'and 45. Thus thereciprocation and resulting impact of the plungers may be selectivelydiscontinued. When the operation of the reciprocating plungers isdiscontinued, the wear plate may be rotated and used as a vibrationlessmeans for achieving a tine iinish on the concrete surface. Thisstep isusually employed after the concrete has reached a relatively smoothsurface -and it is merely necessary to achieve a polishing action on theupper surface `of the concrete without laterally displacing portions ofythe concrete. With such 1an arrangement, it is possible for theoperator to employ both rotary 'and reciprocating motion to displace theconcrete from the peaks into the valleys during the initial stages offinishing the concrete surface and employing only rotary motion toachieve a high degree of finish after Ia relatively smooth surface hasbeen achieved. If the operator then desires to move into a new orunfinished portion of the concrete surface and again employ vibratoryrotation, he merely rotates handle 109 until member 91 moves to `unseatball check valve 93. Simultaneously with the displacement of ball checkvalve 93 from its seat, a passageway is provided between piston members89 and 91, through apertures 111 and y113 to the duid reservoir 85.Helical springs 62 now act to restore plungers 49 to their lowerposition land thus aid ythe iluid under lpressure to cause the fluid inchamber 41 to be driven through conduits 46 land 84 back to reservoir85. When the fluid pressure is equalized by the return of a substantialvolume of iluid `to the reservoir, then handle 169 maybe rotated Itoreseat member 113 in piston member S9 and `to permit ball check valve 93to return Under these conditions, 'the plunger rollers 42 and plungers40 impart vibratory motion to the surface of the concrete by wear plate34 'and the cycle of operations may be repeated.

Thus, it is apparent that this simple concrete finishing machineachieves a high rate of vibratory motion to finish the surface oi theconcrete and this high -rate of vibration is achieved with less powerthan in machines of the type known in the art.

' I-t is also apparent that the fluid system of this machine includes asimple pump to control selectively the actuation of `the reciprocatingplungers by meansof anunusual piston assembly, la' portion of whichpiston assembly acts simultaneously to open a ball check valve and toopen a passageway through the piston which communicates with the uidreservoir.

VWhile the principles of this invention have been explained withreferenceV to one illustrative example, it is understood that they maybe applied to various other equivalent embodiments without departingfrom the spirit and scope `of this invention.

We claim:

Y1. In a concrete linishing machine or the like, a stationary housing, awear plate rotatably mounted relative to said housing, means -forrotating said wear plate, cam surface means `on said Wear plate, impactsurfaces intermediate said Xcam surface means, reciprocating plungermeans mounted in said housing at intervals around said housing abovesaidjcam surface means for selectively engaging said cam surfaces andsaid impact surfaces, tluid actuating means for selectively delivering auid, and uid actuated means coupled to said lfluid actuating means `andslidably coupled to said reciprocating plunger means and having`cooperating shoulders thereon, yeach tluid actuated means having aninternal shoulder cooperating with fan external shoulder on one of saidplunger means for selectively lifting said plunger means out ofengagement with said camvsurfaces and said impact surfaces in responseto the delivery `of lluid from said fluid actuating means to said fluidactuated means.

2. In a concrete nishing machine or the like, according to claim 1wherein said impact surfaces include a plurality of impact lbuttonsdeiining curved surfaces which are'struck by the tips of the saidplungermeans to produce vibratory motion of said wear plate.

3. In a concrete iinishing machine r the like, in accord-ance `withclaim yl wherein said tluid actuating means includes a piston housing, apiston reciprocably mounted in said housing, a valve Vdefining a closureof `one end of said housing and a fluid reservoir having an aperturetherein defining a fluid passage ito said piston housing, said nidactuating means Vincluding means for moving a portion of said pistonrelative to another portion of said piston to provide a iiuid passagebetween said valve and said aperture, and means for reciprocating saidpiston within said housing.

4. In a concrete finishing machine a combination comprising a housing,ya concrete contacting wear plate rotatably mounted relative rto saidhousing and having cam surface means connected thereto, `a plurality ofvibratory plungers reciprocably mounted in said housing at intervalsaround said housing above said cam surface means to f engage said camsurface means at one end of their stroke to produce vibratory motion,said plungers having rollers thereon, said cam surface means beingVpositioned to engage said-rollers, spring means on said plungers formoving said plungers toward said wear plate, piston means slidablyconnected to each'of said plungers, each of said piston means having aninternal shoulder thereon cooperating vwith an external shoulder on oneof said y i plungers for lifting said plunger when said piston means ismoved away `from said wear plate and fluid means for moving said pistonmeans in a direction to disengage said rollers from said cam surfaceswhile said wear plate continues to rotate, selectively to terminate thevibratory motion produced by said plurality 'of plungers.

5. In a concrete nishing machine the combination ac- A cording to claim4 wherein said lluid means comprises a uid reservoir, a piston housingsecured to said reservoir and having a passage communicating therewith,a Vpump piston reciprocably mounted therein, a valve positioned in avalve seat in said housing, springY means ,urging said valve againstsaid valve seat, said pump piston vbeing mov'- able to a position tounseat said Valve from said valve seat.

6. In a concrete nishing machine according to claim 5 wherein said pumppiston comprises an outer cylindrical member having a radial passagetherethrough which cornmunicates with said reservoir only when said pumppiston is at the end of its forwad stroke and an inner rod portion,oneend of which has an outer diameter substantially equal to the innerdiameter of said outer cylindrical member, the other end of which innerrod portion has a diameterk of said outer cylindrical member to providea passage therebetween, which rod portion terminates in an enlargedportion which seats against a recess in the end of `said outercylindrical member to'act as a valve to close the iuid passage throughsaid piston.

`7. In a concrete iinishing machine according to claim 6 the combinationfurther comprising iirst handle means for advancing said inner rodmember with respect to said',

outer cylindrical memiber t0 unseat said enlarged terminal portion ofsaid rod member thereby opening the iluid passage through said pistonand contacting said spring urged valve to open said valve and permit thepassage of uid around said valve, through said piston to said reservoir.

8. The combination according to claim 4 wherein said Y shoulder is onthe inner surface of said piston means and wherein one of said vibratoryplungers is reciprocahly mounted within each of said piston means andhas a shoulder thereon positioned to engage the shoulder on said pistonmeans, said fluid means including means for moving said piston meanswhereby said shoulders engage surface.

References Cited inthe file of this patent UNITED STATES PATENTS1,811,556 2,128,779 Knight Aug. 30, 1938 2,140,970 Reedy Dec. 20, 19382,557,880 Lynn June 19, 1951 2,646,729 Godenir July 28, 1953 l2,680,347Kanuch June 8, 1954 2,723,608 Jackson Nov. 15, 1955 ,2,882,806 fThiemeu;Apr. 21, 1959 FOREIGN PATENTS 311,346 Switzerland Jan. 31, 1956 NilsonJune 23, 1931

